I might be wrong here, but I have always been under the impression that they are the same person. I didn't even realise that is was supposed to be a secret.
Simple things like Lina en Marcan using the same hostname for the development machine (Raider), using the same IDE (Kate), using the same bash aliases (the one I like most if 'stfu' that appears to suppress terminal output), and a huge overlap of knowledge. Then there is also the same fast-paced speaking style that Marcan has.
I did notice Lina always (rather jokingly) denying being Marcan, especially during the April 1 debut, but I always assumed that that was just part of the joke.
Again, I might be wrong here, maybe they are not the same person after all, but as far as I can tell it's just Hector Martin having fun.
> Isn't it the opposite, though?
You mean Lina being first, and Marcan being an alter-ego? Marcan (Hector Martin) is a real person, he has done quite a few interviews on camera. https://youtu.be/dF2YQ92WKpM?t=496